Python中IO多路复用socket[转]

虽然非阻塞socket能够实现单process同时处理多个网络IO事件(client), 但是socket的setblocking是用不断轮询的方式来达到非阻塞处理client的, 所有难免会浪费CPU资源.

然而, epoll(epoll 为linux中效率最高的 IO多路复用), 计算机底层的机制, 可以来检测send, recv等即检测socket是否发生变化(是否出现读写事件), 避免了socket轮询监听浪费资源.

eg: 如果有客户端连接那么server会变为可读事件(也就是socket有数据了可以进行读操作).

使用
server
import socket
import selectors # IO多路复用的选择器. 优于select.

def server_accept(sock):
connected, addr = server.accept()
sel.register(connected, selectors.EVENT_READ, server_recv)

def server_recv(connected):
data = connected.recv(1024)
if data:
print(data.decode('utf-8'))
connected.send(b"I'm received. info: %s" % data)
else:
print("It's over.")
sel.unregister(connected) # 注销socket.
connected.close()

sel = selectors.DefaultSelector() # 选择对应操作系统的技术, win为select linux为epoll.
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((socket.gethostbyname(socket.gethostname()), 4444))
server.listen(5)
sel.register(server, selectors.EVENT_READ, server_accept) # args: socket event callback
print("start listen....")

while True:
try:
events = sel.select()
for key, mask in events:
# 取events中的key元素中的data(为callback), 并传入socket. return is none.
key.data(key.fileobj)

except (BlockingIOError, ConnectionResetError):
pass
      
client
# client
import socket
import time

client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client.connect((socket.gethostbyname(socket.gethostname()), 4444))

while True:
cRequest = input("send: ")
client.send(cRequest.encode())
cResponse = client.recv(1024)
print(cResponse)
if cRequest == "quit":
print("[+] Down line......")
time.sleep(2)
client.close()
break
----------------过程整理------

在server端通过selectors模块，进行两次回调，使用epoll实现IO多路复用。

客户端和普通的socket客户端相同，区别在于server端实现了IO多路复用。

文章出处：https://blog.csdn.net/One_of_them/article/details/81633744